This week's Space Cover of the Week features covers from two unmanned spacecraft that are looong gone: Pioneer 10 and Voyager 1. Pioneer 10 was launched on March 2, 1972, while Voyager 1 was launched on August 20, 1977. On June 13, 1983, Pioneer 10 became the first spacecraft to exit the Solar System. It is continuing on, now after 40 years more than 8 billion miles from Earth. But speedier Voyager 1 had better and further plans. Announced recently, after analysis it was determined that on August 25, 2012, Voyager 1 became the first man-made object to pass into the cold, dark vastness of interstellar space - beyond the influence of the sun. So lonely Voyager 1 continues on, and cruising at a speedy 38,000 mph, it has traveled 11.7 billion miles beyond Earth. Amazingly, it continues to send back data, which takes 17 hours to reach Earth and is expected to continue until about 2025.

Pioneer 10 and Voyager 1 were covered well philatelically, and shown here are covers marking some of Pioneer 10's and Voyager 1's milestones.

The top three covers mark Pioneer 10 milestones, with the top cover canceled at Cape Canaveral for Pioneer 10's departure from the Solar System, and autographed by Charles Hall, Pioneer Program Manager. The middle cover is from the Ames Research Center, with a nice ARC cachet and cancel announcing Pioneer 10 leaving the Solar System. The bottom cover marks Pioneer 10's final transmission on January 22, 2003. It now travels on silently toward red star Aldebaran, 68 light years away (It'll arrive there in about 2 million years!).

The bottom three covers mark Voyager milestones, with the top cover canceled for both Voyager 1 and 2 rollouts to Pad 41, and the middle cover is canceled for both launches, and autographed by top personnel involved in the Titan-Centaur launches boosting Voyager 1 and 2 toward the stars. The bottom cover marks Voyager 1's fly-by of Saturn (following Voyager 2's first encounter) and among others, it is autographed by Voyager Project Scientist, Dr. Ed Stone, now 77 and still involved with Voyager.

In the way of philatelic news concerning Pioneer 10, the KSC HQs building canceled less than 2,000 pieces of mail for the Pioneer 10 launch. Also, on February 28, 1975, the USPS issued a 10-cent stamp commemorating the Pioneer/Jupiter deep-space exploration program. The Pioneer commemorative stamp can be seen above on two covers.

Many other covers exist for various Pioneer 10 and Voyager 1 milestones and events and we would welcome further covers here.

Below my two additions to this SCOTW concerning to long trip made by Voyager 1 during his VIM (Voyager Interstellar Mission).

Below a cover postmarked Pasadena May 24, 2005 marks the entrance in Heliosheath by Voyager 1.

This one, cancelled too in Pasadena marks how the Voyager 1 is already into interstellar space. NASA announced in Sep 12, 2013 that Voyager 1 was into interstellar space from Aug 25, 2012.

Not covers with date Aug 25, 2012 for this event are known at this moment.

Bob M

Thank you for the very important and interesting covers, Antoni. But it is unlikely that we will see any covers for the August 12, 2012 departure of Voyager 1 into interstallar space - unless backdated.

From the article I read about this historic milestone, after analysing data for some time, scientists decided that August 25, 2012 would stand as the "official" and most agreed upon date that Voyager 1 departed into interstellar space.

Ken Havekotte

Bob, A great cover topic for this week's feature. Both incredible missions of Pioneer 10 and Voyager 1 should never be overlooked.

They are, in my opinion, one of man's ultimate adventures to date, along with their twin sister ships of Pioneer 11 and Voyager 2.

As Bob reported, Pioneer 10--the first man-made object to leave our solar system--came to an official end, mission-wise, on March 31, 1997, when it reached a distance of 67 AU from the sun.

Now, more than 41 years in space, Pioneer 10's trajectory is expected to take it in the general direction of the red star Aldebaran, which forms the eye of the constellation Taurus (The Bull), located at a distance of 68 light years from us! It would require more than 2 million years for the 570-pound spacecraft to reach the Aldebaran star area.

Meanwhile, now 36 years later, Voyager 1 is in space between the stars, or better-known as interstellar space from what most scientists have confirmed, and has traveled farther than any human-made object from Earth.

And not to forget that Voyager 2 is the only space probe to have visited the outer planets of Jupiter, Saturn, Uranus and Neptune.

Philatelically speaking, when as a teenage rookie space cover collector in 1972 having witnessed live from the Cape both Pioneer launches (and with both Voyagers five years later), I was intrigued by the mission goals when I first heard about the Pioneer project.

Pioneer 10 presented me with some of my very first cachet cover attempts. Looking back on those early space cover productions of mine, they do indeed seem quite crude and primitive by today's cachet cover standards.

But by just using a good typewriter with some general-purpose rubber stamp impressions that were available at the time, was all it took to get started.

Antoni RIGO

Thanks Bob for opening this interesting topic and especially for your kind words about my covers.

I am absolutely agree with you. If some day appear in the market covers dated Aug 25, 2012 marking the departure of Voyager 1 into interstellar space, they will be "BACKDATED" as this date was established by NASA scientists almost one year later.

Astrophilatelists are accustomed to have in our collections covers for launches or departures and rarely pay attention to final date of the missions/spacecrafts.

Apollo-Soyuz

Here is another Pioneer-10 cover.

Apollo-Soyuz

Some Voyager 1 and Voyager 2 covers.

Antoni RIGO

Most known covers for Voyager missions are normally dated for the planet or moon encounters.

Fortunately, there are covers related to Voyager spacecrafts for other events than above quoted. Some examples:

Bob M

Those are certainly some great and interesting covers for Voyager and Pioneer events, John and Antoni! Thanks for sharing them with us. Obviously, Pioneer 10 and 11, and Voyager 1 and 2 events and milestones were well "covered."